1. Field of the Invention
This invention relates generally to locks, and more particularly to a secondary lock adapted to cover the keyhole of a keyed cylinder primary lock.
2. Description of the Prior Art
One drawback of present day keyed cylinder locks is that the keyhole portion of the cylinder is exposed and thus accessible to tampering or picking. The prior art has suggested several means for protecting the keyhole of a lock cylinder by means of a locking keyhole cover, as shown, for example, in U.S. Pat. No. 3,732,711 to Albert and U.S. Pat. No. 4,365,491 to Rubenstein, et al. However, these mechanisms are somewhat complex to manufacture. Therefore, it is an object of this invention to provide an improved lock mechanism for protecting the keyhole of a keyed cylinder lock, and which is simple to manufacture.
It is another object of this invention to provide a simplified and improved lock mechanism for protecting the keyhole of an integral keyed cylinder lock.